Ink composition, ink cartridge having ink composition, and method of filling ink cartridge

ABSTRACT

An ink composition and an ink cartridge having the ink composition are provided. The ink composition includes a colorant and an aqueous carrier. The ink composition has a dissolved gas content of less than 3 ppm as measured on the basis of the amount of dissolved oxygen gas at 20° C. at 20° C., a static surface tension at 25° C. of greater than 34 dynes/cm, and an advancing contact angle relative to an ink receiving receiver of less than about 55° at room temperature. The ink container can be a collapsible bag.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part of U.S. Ser. No. 09/971,414,filed Oct. 5, 2001 now U.S. Pat. No. 6,585,362, in the name of James W.Blease et al. and assigned to the Eastman Kodak Company.

Reference is made to pending U.S. Ser. No. 09/931,313, entitled InkCartridge With Internal Ink Bag and Method Of Filling, filed in thenames of Winfield R. Trafton, Kirk D. Farnung and Diana C. Petranek onAug. 16, 2001.

FIELD OF THE INVENTION

The present invention relates to ink jet printing and, moreparticularly, to ink compositions used in ink jet printing.

BACKGROUND OF THE INVENTION

Ink jet printing is a non-impact method for producing images by thedeposition of ink droplets in a pixel-by-pixel manner to animage-recording element in response to digital signals. There arevarious methods which may be utilized to control the deposition of inkdroplets on the image-recording element to yield the desired image. Inone process, known as continuous ink jet, a continuous stream ofdroplets is charged and deflected in an imagewise manner onto thesurface of the image-recording element, while unimaged droplets arecaught and returned to an ink sump. In another process, known asdrop-on-demand ink jet, individual ink droplets are projected as neededonto the image-recording element to form the desired image. Commonmethods of controlling the projection of ink droplets in drop-on-demandprinting include piezoelectric transducers and thermal bubble formation.

The inks used in the various ink jet printers can be classified aseither dye-based or pigment-based. A dye is a colorant, which isdissolved in the carrier medium. A pigment is a colorant that isinsoluble in the carrier medium, but is dispersed or suspended in theform of small particles, often stabilized against flocculation andsettling by the use of dispersing agents. The carrier medium can be aliquid or a solid at room temperature in both cases. Commonly usedcarrier media include water, mixtures of water and organic co-solventsand high boiling organic solvents, such as hydrocarbons, esters,ketones, etc.

A requirement in wide format ink jet printers is the delivery of atleast 500 ml of ink through a printhead before nozzles begin to fail tofire ink droplets. In order to achieve this, the ink composition isrequired to have desired physical characteristics including viscosity,surface tension and amount of dissolved gas. The optimized propertylevels are largely dependent on the printer design and printheadarchitecture.

During the ink delivery from an ink cartridge to a printer head, minuteair bubbles present in the ink or within the ink cartridge gives flowresistance to the ink. In addition, when the ink head is repeatedlypressurized and depressurized during ink ejection, dissolved gases (e.g.dissolved oxygen and dissolved nitrogen) present in the ink tend tostagnate in the ink head causing the printhead to misfire during dropletejection resulting in reduced printhead reliability. This isparticularly true in piezoelectric print heads. Additionally, changes inboth ink viscosity and surface tension can cause unreliable dropletejection or droplet splashing which leads to reduced image quality.Typically, inks having a low surface tension (typically less than 40mN/m) tend to have a faster drying time when compared to inks having ahigh surface tension (typically greater than 40 mN/m). However, inkshaving a high surface tension typically produce images of higher imagequality as compared to the images produced by inks having lower surfacetension.

Additionally, inks having properties allowing them to be more easilyabsorbed into a receiver also exhibit shorter drying times. These inkproperties can be described in terms of advancing (forward, etc.)contact angle. For example, inks having advancing contact angles greaterthan 60° relative to a porous receiver, typically, do not penetrate thepore system of the receiver, and, as such, are not absorbed by thereceiver. This can result in longer drying times and can cause anincreased likelihood of image smearing because the ink resides on thereceiver surface for an extended period of time.

U.S. Pat. No. 5,683,500, which issued to Kawasumi et al. on Nov. 4,1997, optimizes an ink composition used in a writing instrument so as toreduced writing defects including uneven ink density and skips in adrawn line. U.S. Pat. No. 5,833,744, which issued to Breton et al. onNov. 10, 1998, optimizes an ink composition by adding a paper specificsurfactant having a paper pulp debonding agent. U.S. Pat. No. 6,288,156B1, which issued to Higashiyama et al. on May 8, 2001, optimizes an inkcomposition for use over a range of temperatures.

An object of the present invention is to optimize the above describedphysical properties of an ink composition so that desired quantities ofink can be delivered by a printhead to a receiver reliability andconsistently over time.

SUMMARY OF THE INVENTION

According to a feature of the present invention, an ink cartridgeincludes a housing having a front side wall, a back side wall oppositethe front side wall, a pair of opposed left and right side wallsseparating the front and the back side walls, and a bottom wall, thewalls defining an internal cavity within the housing. An ink containeris located within the internal cavity and filled with a liquid ink. Theliquid ink has a dissolved gas content of less than 3 ppm as measured onthe basis of the amount of dissolved oxygen gas at 20° C., a staticsurface tension at 25° C. of greater than 34 dynes/cm, and an advancingcontact angle relative to an ink receiving receiver of less than about55° at room temperature.

According to another feature of the present invention, an inkcomposition includes a colorant and an aqueous carrier. The inkcomposition has a dissolved gas content of less than 3 ppm as measuredon the basis of the amount of dissolved oxygen gas at 20° C. at 20° C.,a static surface tension at 25° C. of greater than 34 dynes/cm, and anadvancing contact angle relative to an ink receiving receiver of lessthan about 55° at room temperature.

According to another feature of the present invention, a method offilling an ink cartridge includes providing a housing having a frontside wall, a back side wall opposite the front side wall, a pair ofopposed left and right side walls separating the front and the back sidewalls, and a bottom wall, the walls defining an internal cavity withinthe housing; providing an ink container; positioning the ink containerwithin the internal cavity; and filling the ink container with a liquidink having a dissolved gas content of less than 3 ppm as measured on thebasis of the amount of dissolved oxygen gas at 20° C., a static surfacetension at 25° C. of greater than 34 dynes/cm, and an advancing contactangle relative to an ink receiving receiver of less than about 55° atroom temperature.

According to another feature of the present invention, an ink cartridgeincludes an ink container filled with a liquid ink. The liquid ink has adissolved gas content of less than 3 ppm as measured on the basis of theamount of dissolved oxygen gas at 20° C., a static surface tension at25° C. of greater than 34 dynes/cm, and an advancing contact anglerelative to an ink receiving receiver of less than about 55° at roomtemperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an inkjet printer;

FIG. 1B is a perspective view showing an inkjet printhead used in theprinter of FIG. 1A;

FIG. 1C is a plan view illustrating the nozzle plate for the printheadof FIG. 1B;

FIG. 2 is a perspective view of an ink cartridge receiver assembly usedin the printer of FIG. 1;

FIG. 3 is a top plan view of the ink cartridge receiver assembly of FIG.2;

FIG. 4 is another perspective view of the ink cartridge receiverassembly used in the printer of FIG. 1;

FIG. 5 is a perspective view of an ink cartridge;

FIG. 6 shows a bottom view of the ink cartridge;

FIGS. 7 and 8 show ink cartridge alignment features engaging with theseparators in the ink cartridge receiver assembly;

FIGS. 9A and 9B show how the color identifier keyway and coloridentifier key tab interface when the ink cartridge is placed in thereceiver assembly;

FIG. 10 is an exploded view showing an ink bag, fitment and the septumand ink withdrawal needle which needle forms part of a receptacle in thecartridge receiver assembly;

FIG. 11 is a schematic of a cross-section of the ink cartridgeillustrating support by the internal surfaces of the ink cartridge ofthe filled ink bag;

FIG. 12A and FIG. 12B are front side elevational views of the ink bagthat is to be positioned in the cartridge and showing respectively theink bag in a fully stretched condition and the ink bag when it is notstretched; and

FIG. 13 is a perspective view of the ink bag.

DETAILED DESCRIPTION OF THE INVENTION

The present description will be directed in particular to elementsforming part of, or cooperating more directly with, apparatus andmethods in accordance with the present invention. It is to be understoodthat elements not specifically shown or described may take various formswell known to those skilled in the art.

In order to meet the above described ink delivery performancerequirements, improve image quality, and improve printer performance,the inventors of the present invention have discovered that it isdesirable to reduce the amount of dissolved gas present in an inkcomposition and maintain the surface tension of the ink compositionabove a predetermined level. As such, an ink composition of the presentinvention comprises a colorant and an aqueous carrier, wherein adissolved gas content of the ink composition is less than 3 ppm asmeasured on the basis of the amount of dissolved oxygen gas at 20° C.and a static surface tension of the ink composition at 25° C. is greaterthan 34 dynes/cm. Additionally, ink compositions of this type areparticular suited for use in an ink cartridge having an ink containerpositioned therein, as described below.

The colorant can be a water-soluble dye, a pigment, or any other type ofcolorant provided the colorant can form a color in a water based inkcomposition. Additionally, the colorant can have chromatic color orachromatic color. As referred to in this description and as defined inMeasuring Color, by R. W. G. Hunt, published by Ellis Horwood Limited(1991), the term chromatic color denotes any color exhibiting hue (thesecolors are distinct from those colors commonly referred to as white,gray, black, neutral, and colorless) while the term achromatic colordenotes any color devoid of hue (commonly referred to as white, gray,black, neutral, and colorless colors).

Any water-soluble dye, or combination of dyes, commonly used in an inkcomposition having an aqueous carrier can be used in this invention,such as reactive dyes, direct dyes, anionic dyes, acid dyes, food dyesand the like, for example, those described in U.S. Pat. No. 5,973,026.Additionally, the water-soluble dye can be a cationic dye or an anionicdye. Examples of cationic dyes include azo dyes, such as quaternizedpyrazoleazoaniline dyes, triarylmethane dyes, azine dyes, phthalocyaninedyes, oxazine dyes, thiazine dyes, etc. Examples of anionic dyes includemetal-complex dyes, such as transition metal complexes of8-heterocyclylazo-5-hydroxyquinoline; azo dyes, such as C.I. DirectYellow 132; phthalocyanine dyes such as C.I. Direct Blue 199;anthraquinone dyes, or anthrapyridone dyes; etc. The exact choice of dyewill depend upon the specific application and performance requirementssuch as color reproduction and image stability.

Any known pigment, or combination of pigments, commonly used in an inkcomposition having an aqueous carrier can be used in the invention. Forexample those pigments disclosed in U.S. Pat. Nos. 5,026,427; 5,086,698;5,141,556; 5,160,370; and 5,169,436. The exact choice of pigments willdepend upon the specific application and performance requirements suchas color reproduction and image stability. Pigments suitable for use inthe present invention include, for example, azo pigments, monoazopigments, disazo pigments, azo pigment lakes, β-Naphthol pigments,Naphthol AS pigments, benzimidazolone pigments, disazo condensationpigments, metal complex pigments, isoindolinone and isoindolinepigments, polycyclic pigments, phthalocyanine pigments, quinacridonepigments, perylene and perinone pigments, thioindigo pigments,anthrapyrimidone pigments, flavanthrone pigments, anthanthrone pigments,dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments,diketopyrrolo pyrrole pigments, titanium oxide, iron oxide, and carbonblack. Typical examples of pigments which may be used include ColorIndex (C.I.) Pigment Yellow 1, 2, 3, 5, 6, 10, 12, 13, 14, 16, 17, 62,65, 73, 74, 75, 81, 83, 87, 90, 93, 94, 95, 97, 98, 99, 100, 101, 104,106, 108, 109, 110, 111, 113, 114, 116, 117, 120, 121, 123, 124, 126,127, 128, 129, 130, 133, 136, 138, 139, 147, 148, 150, 151, 152, 153,154, 155, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176,177, 179, 180, 181, 182, 183, 184, 185, 187, 188, 190, 191, 192, 193,194; C.I. Pigment Orange 1, 2, 5, 6, 13, 15, 16, 17, 17:1, 19, 22, 24,31, 34, 36, 38, 40, 43, 44, 46, 48, 49, 51, 59, 60, 61, 62, 64, 65, 66,67, 68, 69; C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 21, 22, 23, 31, 32, 38, 48:1, 48:2, 48:3, 48:4,49:1, 49:2, 49:3, 50:1, 51, 52:1, 52:2, 53:1, 57:1, 60:1, 63:1, 66, 67,68, 81, 95, 112, 114, 119, 122, 136, 144, 146, 147, 148, 149, 150, 151,164, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 181, 184,185, 187, 188, 190, 192, 194, 200, 202, 204, 206, 207, 210, 211, 212,213, 214, 216, 220, 222, 237, 238, 239, 240, 242, 243, 245, 247, 248,251, 252, 253, 254, 255, 256, 258, 261, 264; C.I. Pigment Violet 1, 2,3, 5:1, 13, 19, 23, 25, 27, 29, 31, 32, 37, 39, 42, 44, 50; C.I. PigmentBlue 1, 2, 9, 10, 14, 15:1, 15:2, 15:3, 15:4, 15:6, 15, 16, 18, 19,24:1, 25, 56, 60, 61, 62, 63, 64, 66; C.I. Pigment Green 1, 2, 4, 7, 8,10, 36, 45; C.I. Pigment Black 1, 7, 20, 31, 32, and C.I. Pigment Brown1, 5, 22, 23, 25, 38, 41, 42. In a preferred embodiment of theinvention, the pigment is C.I. Pigment Blue 15:3, C.I. Pigment Red 122,C.I. Pigment Yellow 155, C.I. Pigment Yellow 74,bis(phthalocyanylalumino)tetraphenyldisiloxane or C.I. Pigment Black 7.

If a pigment is used as the colorant, a pigment dispersant can be addedto the ink composition. Pigment dispersants include water-solubleresins, surface active agents, and the like. Examples of water-solubleresins include natural resins, semi-synthetic resins, synthetic resins,etc. Examples of synthetic resins include alkali-water-soluble resinssuch as polyacrylic acid resins, polymaleic acid resins, styrene-acrylicacid copolymers and styrene-maleic acid copolymers, water-solublestyrene resins, polyvinyl pyrrolidone, polyvinyl alcohol, water-solubleurethane resins, etc. Examples of surface-active agents include anionicsurface-active agents, cationic surface-active agents, nonionicsurface-active agents, ampholytic surface-active agents, etc.

Typically, the aqueous carrier for the ink composition is water or amixture of water and at least one water miscible co-solvent. Selectionof a suitable mixture depends on requirements of the specificapplication, such as desired surface tension and viscosity, the selectedpigment or dye, drying time of the ink jet ink, and the type of paperonto which the ink will be printed. Representative examples ofwater-miscible co-solvents that may be selected include (1) alcohols,such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropylalcohol, n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, iso-butylalcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol; (2) ketonesor ketoalcohols such as acetone, methyl ethyl ketone and diacetonealcohol; (3) ethers, such as tetrahydrofuran and dioxane; (4) esters,such as ethyl acetate, ethyl lactate, ethylene carbonate and propylenecarbonate; (5) polyhydric alcohols, such as ethylene glycol, diethyleneglycol, triethylene glycol, tetraethylene glycol, propylene glycol,polyethylene glycol, glycerol, 2-methyl-2,4-pentanediol1,2,6-hexanetriol and thioglycol; (6) lower alkyl mono- or di-ethersderived from alkylene glycols, such as ethylene glycol mono-methyl (or-ethyl) ether, diethylene glycol mono-methyl (or -ethyl) ether,diethylene glycol mono-butyl (or -ethyl) ether, propylene glycolmono-methyl (or -ethyl) ether, poly(ethylene glycol) butyl ether,triethylene glycol mono-methyl (or -ethyl) ether and diethylene glycoldi-methyl (or -ethyl) ether; (7) nitrogen containing cyclic compounds,such as pyrrolidone, N-methyl-2-pyrrolidone, and1,3-dimethyl-2-imidazolidinone; and (8) sulfur-containing compounds suchas dimethyl sulfoxide, 2,2′-thiodiethanol, and tetramethylene sulfone.

Typically, the amount of aqueous carrier employed is in the range ofapproximately 70 to 98 weight %, preferably approximately 90 to 98weight %, based on the total weight of the ink. A mixture of water and apolyhydric alcohol, such as diethylene glycol, is useful as an aqueouscarrier. In a preferred embodiment, the inks contain from about 5 toabout 60 weight % of water miscible organic solvent. Percentages arebased on the total weight of the aqueous carrier.

Water-miscible organic solvents may also be added to the ink compositionin order to help the ink penetrate the receiving substrate, especiallywhen the substrate is a highly sized paper. Examples of such solventsinclude alcohols, such as methyl alcohol, ethyl alcohol, n-propylalcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butylalcohol, iso-butyl alcohol, furfuryl alcohol, and tetrahydrofurfurylalcohol; ketones or ketoalcohols such as acetone, methyl ethyl ketoneand diacetone alcohol; ethers, such as tetrahydrofuran and dioxane; andesters, such as, ethyl lactate, ethylene carbonate and propylenecarbonate.

Other additives which may optionally be present in the ink jet inkcompositions include thickeners, conductivity enhancing agents,anti-kogation agents, drying agents, waterfast agents, dye solubilizers,chelating agents, binders, light stabilizers, viscosifiers, bufferingagents, anti-mold agents, anti-curl agents, stabilizers and defoamers.Additionally, the ink compositions can include a humectant, asurfactant, a penetrant, a biocide, etc. as is required depending on theapplication.

A humectant is usually employed in the ink jet compositions of theinvention to help prevent the ink from drying out or crusting in theorifices of the printhead. Examples of humectants which can be usedinclude polyhydric alcohols, such as ethylene glycol, diethyleneglycol(DEG), triethylene glycol, propylene glycol, tetraethylene glycol,polyethylene glycol, glycerol, 2-methyl-2,4-pentanediol,2-ethyl-2-hydroxymethyl-1,3-propanediol(EHMP), 1,5 pentanediol,1,2-hexanediol, 1,2,6-hexanetriol and thioglycol; lower alkyl mono- ordi-ethers derived from alkylene glycols, such as ethylene glycolmono-methyl or mono-ethyl ether, diethylene glycol mono-methyl ormono-ethyl ether, propylene glycol mono-methyl or mono-ethyl ether,triethylene glycol mono-methyl, mono-ethyl or mono-butyl ether (TEGMBE),diethylene glycol di-methyl or di-ethyl ether, poly(ethylene glycol)monobutyl ether (PEGMBE), and diethylene glycol monobutylether(DEGMBE);nitrogen-containing compounds, such as urea, 2-pyrrolidinone,N-methyl-2-pyrrolidinone, and 1,3-dimethyl-2-imidazolidinone; andsulfur-containing compounds such as dimethyl sulfoxide andtetramethylene sulfone, etc.

Preferred humectants for the inks of the invention include DEG,glycerol, DEGMBE, TEGMBE, 1,2-hexanediol, 1,5-pentanediol, urea,2-pyrrolidinone, EHMP and mixtures thereof. The humectant may beemployed in each ink in an amount of from about 5 to about 60 weightpercent.

Surfactants may be added to the ink to adjust the surface tension to anappropriate level. The surfactants may be anionic, cationic, amphotericor nonionic and used at levels of 0.01 to 1% of the ink composition.Preferred surfactants include Surfynol® 465 (available from Air ProductsCorp.) and Tergitol® 15-S-5 (available from Union Carbide).

A penetrant (0-10% by weight) may also be added to the ink compositionemployed in the process of the invention to help the ink penetrate thereceiving substrate, especially when the substrate is a highly sizedpaper. A preferred penetrant for the inks of the present invention isn-propanol at a final concentration of 1-6% by weight.

A biocide may be added to the ink composition employed in the inventionto suppress the growth of microorganisms such as molds, fungi, etc. inaqueous inks. A preferred biocide for the ink composition employed inthe present invention is Proxel® GXL (Avecia Corp.) at a finalconcentration of 0.0001-0.5 wt. %.

The pH of the aqueous ink compositions employed in the invention may beadjusted by the addition of organic or inorganic acids or bases. Usefulinks may have a preferred pH of from about 2 to 10, depending upon thetype of dye being used. Typical inorganic acids include hydrochloric,phosphoric and sulfuric acids. Typical organic acids includemethanesulfonic, acetic and lactic acids. Typical inorganic basesinclude alkali metal hydroxides and carbonates. Typical organic basesinclude ammonia, triethanolamine (TEA) and tetramethylethlenediamine.

A typical ink composition employed in the invention may comprise, forexample, the following components by weight: colorant (0.05-20%), water(20-95%), a humectant (5-70%), water miscible co-solvents (2-20%),surfactant (0.1-10%), biocide (0.05-5%) and pH control agents (0.1-10%).Examples of ink compositions made in accordance with the presentinvention include the following.

Example Ink Formulations

Wt. % Wt. % Wt. % Wt. % PEG Wt. % Ink Dye(s) Dye(s) glycerol DEG MBE TEAEx. 1 Avecia Projet Fast Cyan 2 3.6 9.5 12.5 7.0 0.9 Cyan Ex. 2 NipponKayaku JPD-EK1, 3.00 9.0 11.5 7.5 0.9 Magenta Sensient Reactive Red 310.86 Ex. 3 Avecia Projet Yellow 1G 4.0 15.5 3.0 9.0 0.9 Yellow Ex. 4Clariant Duasyn KRL-SF 5.0 8.0 11.25 8.5 Black Ex. 5 Avecia Projet FastCyan 2 1.2 11.75 13.5 7.0 0.5 Light Cyan Ex. 6 Nippon Kayaku JPD-EK1,0.9 11.3 13.5 7.5 0.3 Light Sensient Reactive Red 31 0.24 Magenta Ex. 7Avecia Projet Fast Cyan 2 3.0 5.5 5.5 11.0 1.3 Cyan Ex. 8 Avecia ProjetFast Cyan 2 3.0 9.5 9.5 3.0 1.3 Cyan Ex. 9 Avecia Projet Fast Cyan 2 3.015.5 15.5 11.0 1.3 Cyan Ex. 10 Avecia Projet Fast Cyan 2 3.0 19.5 19.53.0 1.3 Cyan

COMPARATIVE EXAMPLES

Comparative examples 1 through 6 correspond to Examples 1 through 6having a dissolved gas content of the ink composition was greater than 3ppm as measured on the basis of the amount of dissolved oxygen gas at20° C.

Com. Epson Cyan Ink T410 Ex. 7 (for the Epson Stylus Pro 9000 Printer)Com. Epson Cyan Ink T502 Ex. 8 (for the Epson Stylus Pro 10000 Printer)Wt. % Wt. % 2- Wt. % Inks Dye(s) Dye(s) pyrrolidinone 1,2-hexanediolCom. Clariant Duasyn 12.0 12.0 6.0 Ex. 9 KRL-SF Black

Testing Procedures

Ink viscosity can be measured by any suitable means known in the art.For the ink compositions of the invention and the comparative examples,a temperature controlled capillary viscometer was used. The viscometeremploys an electronic balance to collect the ink that leaves thecapillary tube so that a mass flow rate at steady state can bedetermined. The capillary tube is made from glass and has a diameter of0.1 centimeter and is temperature controlled by a water jacket. All inkmeasurements were made at 25° C.

Ink viscosity is calculated from the Poiseuille equation shown below.$\mu = \frac{\rho^{2}{g\left( {h + L} \right)}\pi \quad D^{4}}{128{Lq}}$

In the equation, μ is the ink viscosity, g is the gravitationalconstant, h is the height of the liquid sample above the capillary tube,L is the length of the capillary tube, D is the diameter of thecapillary tube, ρ is the density of the ink to be tested and q is theaverage mass flow rate of the ink.

Measurement of dissolved gas (O₂ and N₂) in the ink compositions of theinvention can be accomplished using a gas chromatography methoddescribed in Table 1 and accompanying text set forth below.

TABLE 1 Material Inks (dye and pigment) Test(s) O₂ and N₂ (ug/g Ink)Column J & W Scientific Molesieve (30 m × 0.53 mm × 25.0 um) InstrumentAgilent 6890 GC with manual Purge and Trap device Temperature InitialTemperature (° C.): 30, Initial Time Gradient (min): 5.5; Rate (°C./min): 15, Temperature (° C.): 60; Rate (° C./min): 30, FinalTemperature (° C.): 250; Final Time (min): 4 Purge and Trap Purge Time(min): 5.5, Trap Time (min): 5.5 (liquid N₂) Detector 300° C.Temperature (° C.) Gases Carrier: Helium, Pressure (psi): 12 psi, Splitflow (ml/min): 60 (empty purge vessel), Makeup (ml/ min): 7 (constant),Reference (ml/min): 20 Detector Thermal Conductivity (TCD) IntegratorAgilent ChemStation (Version A.06.01)

Standard Preparation: Inject 10, 20, 30, and 50 uL of Air into Purgevessel (through septum) using a gas tight syringe. Quantification isbased on a method of external standards. Background air (O₂, N₂) isdetermined by placing a section of the column in liquid N₂ for 5.5 min.O₂ and N₂ areas in the background are then subtracted from that of thestandards and samples.

Sample Preparation: Pierce septum of ink bag with the needle of a 2 mLVICI Pressure Lok syringe, withdraw 0.5 mL ink, and then discard ink.Re-pierce septum and draw 1.3 mL of ink into the syringe. Lock in thesample by pushing the red button until it stops against the frontsleeve. Remove needle from syringe tip and attach syringe to Purgevessel. Open purge and syringe valves and push 0.3 mL of sample (until1.0 mL mark) into the purge vessel, then close valves. This step removesthe air present between the syringe and the purge vessel. Waitapproximately 1 min after air elutes from the column and then insert asection of the column into a dewar of liquid N₂. Immediately open purgeand syringe valves and add remaining sample (1.0 mL) to the purgevessel. Purge/trap time is 5.5 mL. After 5.5 min, remove column from thedewar of liquid N₂. Switch purge valve to “blow out” sample after thecompletion of the chromatographic run. Component O₂ can be identifiedbased on the retention time of approximately 6.5 minutes while componentN₂ can be identified based on the retention time of approximately 6.8minutes.

Alternatively, measurement of dissolved oxygen (O₂) in the inkcompositions of the invention can be accomplished using a dissolvedoxygen (DO) meter described in Table 2 and accompanying text set forthbelow.

TABLE 2 Material Inkjet Inks Test Dissolved Oxygen Concentration, O₂,PPM Instrument Mettler-Teledo Model 4100 Meter equipped with oxygensensing electrode Model 6100. Available from Mettler-Toledo ProcessAnalytical, Inc, Woburn MA. Calibration Room air and high purity HeliumSample Ink cartridge

Calibration Procedure: Single point calibration of Model 4100 DO meteris done according to the recommended procedure of suspending the DOprobe in air and adjusting the digital read out to 8.5 PPM O2. Atwo-point calibration is the run using the same procedure with an addedstep of adjusting the zero PPM O2 concentration while suspending the DOprobe in a stream of high purity He.

Sample Preparation: The degassed ink sample is contained in a flexibleplastic laminate pouch housed in a sealed plastic cartridge. The plasticcartridge is cut opened sufficiently to expose one end of the plasticpouch. The pouch is then cut open only sufficiently to allow insertionof the metal DO probe.

Sample Measurement Procedure: With an occasional very gentle stirringaction using the probe itself inside the pouch, a steady-state DOreading is taken after approx. 10-20 minutes.

Alternative Sample Measurement Procedure: The ink can be drained fromcartridge for measurement by insertion of a needle into the pouchthrough its septum or pouch wall. The needle is attached to a shortsection of flexible tubing which in turn is attached to a “T” housingavailable from Mettler-Toledo (Model no. 724DO2). The “T” housing holdsthe DO probe in such a way as to allow the ink to flow past the tipwithout contacting the ambient atmosphere. After approx. 30-50 ml of inkhas flowed through the “T” housing an accurate and reproducible O2measurement can be taken.

Static surface tension of the ink can be measured by any suitable meansknown in the art. For the ink compositions of the invention and thecomparative examples, a temperature controlled surface tension apparatusemploying the Wilhemy plate method was used. Such an apparatus is the K10 ST Digital Tensiometer manufactured by Kruss GmBH. All inks weremeasured at 25° C. Ink surface tension is calculated from the equationshown below. $\sigma = \frac{P_{w}}{l_{b}\cos \quad \theta}$

In the equation, σ is the static surface tension, P_(w) is the measuredforce, l_(b) is the wetting length (40 mm for the Kruss tensionmeter)and θ is the contact angle between the plate and the ink. The viscometerautomatically determines the static surface tension of the sample inkwhen operated according to the manufacturer's procedure.

Advancing (forward, etc.) contact angle of the ink compositions can bemeasured by any suitable means known in the art. For the inkcompositions of the present invention and the comparative examples, anautomated dynamic contact angle apparatus was used to measure advancingcontact angle. Measurements of ink advancing contact angle were taken atroom temperature (20-25° C.) using a DAT 110 Model Dynamic Contact Angleand Absorption Tester manufactured by FIBRO Systems AB following ASTM(American Society for Testing and Materials) test method D5725-95.

In ASTM test method D5725-95, a droplet of liquid (ink) of a specificvolume is applied to a receiver surface using a micro-pipette undercontrolled conditions. The behavior of the drop on the receiver surfaceis continuously recorded using an electronic video camera. A tiltingtable on which the receiver sits enables determination of the advancingcontact angle. The advancing contact angle was taken to be the angle atwhich the drop reaches its maximum radius. The receiver used to measurethe advancing contact angle for the ink compositions of the inventionand the comparative examples was Kodak Instant Dry Glossy Media,commercially available from Eastman Kodak Co, Rochester, N.Y.

Results

Ink compositions having various dissolved gas levels, surface tensions,and viscosities were tested by firing the ink compositions through aBROTHER piezoelectric type drop on demand ink jet printhead. Asuccessful test result occurred when 67 pL ink droplets of the inkcomposition were continuously fired through the printhead at a rate of7,500 drops/second for at least 5 minutes without nozzle failure or inkdroplet misdirection. The results are described in the table below.

Surface tension Ad- Viscosity @ vancing Dissolved @ 25° C. contactPackage Oxygen 25° C. dynes/ angle Test Ink comp. Types ppm cp cmdegrees Results Ex. 1 Bag <3 2.9 40 21.4 OK Ex. 2 Bag <3 2.8 39 25.1 OKEx. 3 Bag <3 2.9 39 21.5 OK Ex. 4 Bag <3 2.8 39 22.1 OK Ex. 5 Bag <3 2.839 21.2 OK Ex. 6 Bag <3 2.8 39 21.2 OK Ex. 7 N/A <3 2.3 36 19.9 OK Ex. 8N/A <3 2.0 44 20.9 OK Ex. 9 N/A <3 4.4 36 22.9 OK Ex. 10 N/A <3 4.2 4322.6 OK Com Ex. 1 BAg >3 2.9 40 21.4 Failed Com Ex. 2 Bag >3 2.8 39 25.1Failed Com Ex. 3 Bag >3 2.9 39 21.5 Failed Com Ex. 4 Bag >3 2.8 39 22.1Failed Com Ex. 5 Bag >3 2.8 39 21.2 Failed Com Ex. 6 Bag >3 2.8 39 21.2Failed Com Ex. 7 Bag 0.4-0.6 3.3 33 — Failed Com Ex. 8 Bag 0.3 3.1 29 —Failed Com Ex. 9 N/A <3 2.4 34 — Failed

The ink compositions have physical properties compatible with a widerange of ink ejecting conditions, i.e., driving voltages and pulsewidths for thermal ink jet printing devices, driving frequencies of thepiezo element for either a drop-on-demand device or a continuous device,and the shape and size of the nozzle.

The viscosity of the ink compositions of the present invention iscontrolled to fall in a range from 2.0 to 10 cps and preferably from 2.5to 3.5 cps. When the viscosity is lower than 2.0 cps, poor dropletejection occurs resulting in multiple randomly sized dots in irregularlocations on the printed media. When the viscosity is higher than 10cps, the printhead's ability to eject a droplet is reduced increasingthe possibility of permanent nozzle clogging.

The surface tension of the ink compositions of the present invention isgreater than 34, preferably from 34 mN/m to 45 mN/m, and more preferablyfrom 36 to 40 mN/m. When the surface tension is lower than the abovedescribed range, the printhead failed to fire continuously for at least5 minutes. Although a preferred embodiment has a surface tension rangeof from 36 to 40 mN/m, the surface tension can be higher than 40 mN/m.When the surface tension exceeds 40 mN/m, the droplet's ability topenetrate the receiver can be reduced and the overall drying time of theimage can be increased.

The amount of dissolved gas of the ink jet ink of the present inventionis controlled to be no greater than 3.0 ppm as measured on the basis ofthe amount of dissolved oxygen gas at 20° C. and preferably no greaterthan 1.0 ppm. When the amount of dissolved gas is higher than the abovedescribed range, the printhead failed to fire continuously for at least5 minutes.

The advancing contact angle relative to an ink receiving receiver of theink compositions of the present invention is less than 60°, preferablyless than 55°, more preferably less than 50°, more preferably less than30°, more preferably less than 25°, and more preferably less than 20° asmeasured at room temperature (approximately 20-25° C.). Generally,advancing contact angles approaching 60° or greater inhibit rapidabsorption of the ink into the receiver. However, the ink compositionsof the present invention exhibited improved absorption rates as comparedto the ink compositions of the comparative examples.

Referring to FIGS. 1A-C, an embodiment of a printer 10 that is adaptedto accept a plurality of the ink cartridges, each cartridge having anink composition described above as a main ink supply. The printerincludes a carriage 11 that supports an ink jet print head for movementduring printing. The ink jet print head is mounted on a print headmodule 25 (FIG. 1B) which in turn is mounted to the carriage 11. Thecarriage 11, is coupled through a timing belt 13 with a drive motor (notshown), is reproducibly movable along the width of a recording medium 12(in the directions of arrows A and B in the FIG. 1A), while being guidedby a guide member 15. The ink jet print head 31 receives ink from theink tank or cartridge 16 through an ink supply tube 17. An intermediatesupply of ink may be provided between the ink cartridge and printhead,and thus the ink cartridge may be considered a bulk supply of the ink ofa particular color for the printer. A sheet transport roller 18, whendriven by a drive motor (not shown), transports the recording medium 12in the direction (of arrow C in the FIG. 1A) perpendicular to the movingdirection of the carriage 11.

A Raster Image Processor controls image manipulation and the resultantimage file is delivered to the printer via a remotely located computerthrough a communications port. On board memory stores the image filewhile the printer is in operation.

FIGS. 1B and 1C show an embodiment of a piezoelectric print head moduleor assembly 25. However, the ink cartridge may be used with otherdrop-on-demand print heads such as thermal inkjet print heads andcontinuous inkjet print heads. Reference numeral 36 designates a nozzleplate having nozzle openings 37 formed therein. Numeral 38 indicates anink supply port through which ink flows from the ink cartridges 16 viathe ink supply tube 17. The firing rate of the print head 31 can beswitched between 7.5 kHz and 15 kHz depending on the selection of imageresolution and print quality. The carriage velocity is fixed in allprint modes.

With reference to FIGS. 2-6 there is shown a printer main ink supply 19that includes a plurality of different color ink containing inkcartridges 16 and ink cartridge receiver assembly 20 that includesindividual cartridge receiving receptacles for receiving each cartridge.Six ink cartridges 16 are positioned in the assembly housing of the inkcartridge receiver assembly such that they are each separated by adivider wall or spacer wall 23 that forms a part of the receiverassembly. The ink cartridge 16 is comprised of a housing 50 with anon-symmetrical curvaceous profile 51, integrated hand hold features orhandle 53, cartridge alignment features 52, ink cartridge coloridentifier or color or ink type discrimination structure 60, and amemory chip assembly 55. An ink bag 70 is also supported within thecartridge and contains ink of a particular color. Typically, the inkcolor used may be cyan, magenta, yellow and black. Different shades ofone or more of these colors may also be provided. Thus, for example,there may be provided cartridges with different shades of cyan. A spotcolor may also be provided, thus providing an option for use of a veryparticular color.

The cartridge housing includes an ink receiving cavity, and the housingis defined by a front side wall 90, a back side wall 91 opposite thefront side wall, a left side wall 94 and a right side wall 93, the leftside wall and the right side wall each respectively establishing aspacing between the front side wall and the back side wall. A bottomwall 95 is also provided from which ink is removed from the inkcartridge. The front side wall and the back side wall are curved so thatan outer surface of one has a generally convex curvature and the outersurface of the other has a concave curvature. A plurality of alignmentrecesses or features 52 are formed on the surfaces of the cartridgehousing. A first alignment recess 52 is formed on the outer surface ofthe front side wall and a pair of alignment recesses 52 are formed onthe outer surface of the back side wall. The three alignment recessesare formed adjacent to the bottom wall and the first alignment recess islocated substantially midway between the pair of alignment recesses inthe width-wise direction of the ink receiving cavity. It will be notedfrom the figures that the recesses 52 are each relatively elongated inthe direction of the height of the cartridge and this is advantageoussince the cartridge is inserted with the bottom of the cartridge movingtowards the bottom of the ink cartridge receiving receptacle. Therefore,the elongation of the recesses are in the direction of insertion of thecartridges into a respective receptacle. The walls of the ink cartridgeare relatively rigid to provide a rigid cartridge structure.

A plurality of identical spacer walls spaced equally from each other inthe assembly housing also have cartridge alignment structures 24 thereon(see also FIGS. 6 and 7). Each spacer wall 23 has a curvature to receivea cartridge having a generally complementary curvature to the curvatureof the spacer wall. Adjacent spacer walls 23 define a cartridgereceiving receptacle and have facing surfaces wherein the location ofalignment structures 24 are not identical since the alignment recesseson the front and back surfaces of the cartridge are not identical.

The curvaceous profile 51 of the cartridge 16 is comprised of variousradii and appears in a wave shape. This shape can be othernon-rectangular shapes such that when nested with other cartridges theorientation of insertion is uni-directional. The provision of a curvedshape to the ink cartridge provides a visual aid in describing theproper orientation of the ink cartridge before insertion. The generalshape of the cartridge and that of the cartridge receiving receptacleforming a part of the cartridge receiver assembly prevents the cartridgefrom being inserted incorrectly. This permits electrical contactsforming a part of the memory chip assembly to be aligned with electricalcontact members 21 (FIG. 4) in the receptacles of the cartridge receiverassembly 20. The curvaceous profile 51 also stabilizes the ink cartridgewhen in storage by providing nesting action as cartridges are stackedone on top of the other.

The ink cartridge housing (FIGS. 5, 6) includes integral alignmentfeatures 52 that are molded into the plastic cartridge that mate orcooperate with location structures or features formed in the receptaclesof the ink cartridge receiver assembly 19 (FIG. 3). The opening of eachreceptacle is significantly larger than the ink cartridge allowing foreasy insertion. The ink cartridge's alignment features 52 engage withmating location features 24 on the divider or spacer walls 23 (FIG. 7)as the ink cartridge 16 is being inserted into the proper receptacle ofthe ink cartridge receiver assembly 19. Engagement of these featuresoccurs before the receptacle's ink color identifier key and needleapproach the cartridge fitment 71 and septum 72 (FIG. 10). Thesefeatures align the ink cartridge 16 such that the hollow needle 74aligns with and pierces the septum 72. The cartridge alignment features52 also align the ink cartridge such that the electrical contact members21 (FIG. 4) of each cartridge receiving receptacle are positioned toengage the counterpart electrical contacts 58 of memory chip assembly 55(FIGS. 13A and 13B) on the ink cartridge 16. It is important to notethat the divider walls 23, the ink cartridge housing 50 (FIG. 5) andcolor identifier (color or ink type discrimination structure) 60 are thesame parts used repeatedly in the ink cartridge assembly 20. Thedifference from one color cartridge to the next is the orientationdifference of the color identifier 60 in concert with the orientationdifference of the color identifier key tab 67 (see FIGS. 9A and 9B) fromone cartridge receiving receptacle to another cartridge receivingreceptacle. This design therefore minimizes the manufacturing cost ofthe ink cartridge assembly 20 by using a minimum number of uniquecomponents.

With reference to FIGS. 10, 19A and 19B, and 13 illustrate detailsregarding the construction of the ink bag 70 that is located within thecartridge. The fitment 71 is thermally sealed to the bag material. Theflexible ink bag material is composed of three layers with adhesivebetween each layer. Each layer has a specific purpose by providingeither compatibility with the ink, low water vapor and gas permeability,or abrasion resistance. The inside layer, in contact with the ink, iseither a linear low density or low density polyethylene. The fitment ismade from either a low-density or a high-density polyethylene therebypromoting good adhesion of it to the bag during the thermal weldingprocess. The middle layer is aluminum foil providing low water vapor andgas permeability, and the outer layer is either nylon or polyethyleneterepthalate having high strength and abrasion resistance. The septum 72is inserted into the circular opening of the fitment 71. The insidediameter of the circular opening of the fitment is smaller than theoutside diameter of the septum creating a slight compression of theseptum once inserted into the fitment. Once assembled, the bag, fitmentand septum must allow for an efficient filling and evacuation process. Afeature to the function of the ink bag is the taper angle 73 illustratedin FIG. 10.

It is important to minimize the amount of trapped air remaining in thebag once filled with ink. If air remains in the bag it will dissolveinto the ink between the time of manufacture and usage. Dissolved gasesin the ink will come out of solution during the firing process of thepiezoelectric print head and form air bubbles. Air bubbles, beingcompressible, will prevent the nozzles from expelling a drop of ink ontothe print media 12. The taper angle 73 helps expedite the evacuation ofair in the bag during the filling process and allow for a majority ofthe ink to drain from the bag during usage.

During the filling process the bag is evacuated of air before ink isinjected into it. When the ink bag is full the remaining air, now nearthe fitment and septum, is evacuated. If the taper angle is not presentthe air tends to become trapped in the corners of the bag and can not beevacuated. The angle allows the remaining air to move to the fitment andthereby allows for its removal. The taper angle 73, which is formed fromthe area of the bag near the fitment and tapers to a vertical side edgeof the bag should be between 5 and 45 degrees. In the preferredembodiment a taper angle of 15 degrees is provided.

Another contributor to the performance of the ink bag is therelationship between the cartridge housing size and shape and the sizeand shape of the bag 70. When the ink bag is full of ink (see FIG. 11),and contained within the ink cartridge housing 50, the ink bag isconstrained by four interior sides of the ink cartridge housing 50.Therefore the capacity of the ink bag within the ink cartridge housingis driven by the optimization of the size of the ink cartridge housing50. Key to this optimization is the aspect ratio of the ink cartridgehousing size, which in turn drives the size of the ink bag 70.

The method utilized in the assembly of the ink cartridge is benefited bythe design. The advantage of sizing the ink bag and cartridge housingaccording to the relationships stated above allows for the assembly ofthe ink bag to the cartridge housing before the ink filling process isinitiated. The process of assembly includes evacuating the ink bag ofair, laying the first half of the cartridge housing on its side, placingcolor identification components around the fitment of the ink bag, andinserting the ink bag into the first housing using two sided tape. Theinsertion of the bag is made such that the empty ink bag is conformed tothe profile of the first housing half, taped in place using double-sidedtape, and then covered with the second housing half. The first andsecond housings halves are then ultrasonically welded together. Theultrasonic welding process providing a low cost assembly method althoughother known methods may be used.

Once the housing assembly is welded, the ink bag is filled with a knownamount of ink (for example, 1100 mL) while lying on its side and byplacing a needle through the septum and pumping ink through the needleand into the ink bag. The cartridge assembly is then turned verticallysuch that the fitment and septum are facing up. The cartridge may bebumped to cause air in the ink to rise to the top of the bag. Theremaining air and about 50 mL of ink are then removed from the bag byapplying a vacuum through the needle. At this point the ink bag is fullyconstrained by the housing and the surface of bag is in intimate contactwith the four inside surfaces of the housing assembly as illustrated inthe horizontal sectional view shown in FIG. 11. This prevents the bagfrom shifting during transport. If shifting were to occur then the bagsurface could potentially abrade and rupture resulting in ink leakage.If the ink bag was filled prior to the ultrasonic welding process it mayalso become abraded from the welding process and subsequently rupture.The method of assembly and the configuration of the housing in concertwith the ink bag together result in a low cost ink cartridge assembly.As may be noted from FIG. 11 at the section shown there is a uniforminternal cartridge cavity thickness spacing between corresponding pointson the respective internal surfaces of the front and back side wallseven though the front and back sides are curved as are their internalsurfaces. The front and backsides are curved complementary; for exampleone is generally concave in curvature and the other is generally convexin curvature, but internally they maintain a generally uniform spacingbetween corresponding points on the internal surfaces at least along acertain section through the cartridge.

The ink compositions are degassed prior to filling. During the degassingprocess, ink is pumped to a degassing unit and cycled until the inkreaches a desired gas level. Once reaching the desired gas level, theink is ready for the filling process. The degassing unit may incorporateknown mechanisms for removing dissolved gases from an ink. Theseinclude, but are not limited to, physical processes such as boiling andevacuation, and chemical processes such as incorporating gas absorbentsin the inks. Furthermore, additional heating, vibration, and evacuationmethods can also be incorporated. These include, for example, the use ofmicrowave energy as described in U.S. Pat. No. 5,341,162 and U.S. Pat.No. 6,089,702; the use of ultrasonic wave generator as described in U.S.Pat. No. 3,904,392 and U.S. Pat. No. 5,373,212; and the use of agas-permeable hollow fiber membrane as described in EP 1052011A1 and JP05-317605 A2; a commercially available Liquid-Cel membrane cartridgemanufactured by Celgard KK. Alternatively, other degassing processes canbe used.

Although it is preferable to incorporate a collapsible bag in the inkcartridge, non-collapsible bags, or rigid ink containers can also beused provided the level of dissolved gas in the ink composition remainssubstantial constant. Additionally, printers using cartridges having inkbags that are sealed and not vented to the atmosphere but insteadcollapse as the ink is used have advantages over printers using othertypes of ink cartridges, for example, cartridges that vent to theatmosphere or incorporate additional components (e.g. an ink absorbingsponge) into the ink cartridge. Using an ink cartridge having acollapsible bag allows the low level of dissolved gas in the inkcomposition to be maintained during printing. This can be contrastedwith an ink cartridge that vents to the atmosphere which allows thelevel of dissolved gas in the ink composition to increase over time oncethe ink cartridge is connected to the printer. This, in turn, can leadto degraded ink performance during printing. Additionally, if additionalcomponents are incorporated into the ink cartridge, small pieces orparticles of the incorporated component can break away causingcontamination of the ink. This may eventually cause nozzles to becomeclogged, degrading the quality of the image produced.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

What is claimed is:
 1. An ink cartridge comprising: a housing having afront side wall, a back side wall opposite the front side wall, a pairof opposed left and right side walls separating the front and the backside walls, and a bottom wall, the walls defining an internal cavitywithin the housing; an ink container located within the internal cavityand filled with a liquid ink, the liquid ink having a dissolved gascontent of less than 3 ppm as measured on the basis of the amount ofdissolved oxygen gas at 20° C., a static surface tension at 25° C. ofgreater than 34 dynes/cm, and an advancing contact angle relative to anink receiving receiver of less than about 55° at room temperature. 2.The ink cartridge according to claim 1, wherein the ink container is abag.
 3. The ink cartridge according to claim 1, wherein the advancingcontact angle relative to an ink receiving receiver of less than 30° atroom temperature.
 4. The ink cartridge according to claim 1, wherein thedissolved gas content is less than 1.0 ppm as measured on the basis ofthe amount of dissolved oxygen gas at 20° C.
 5. The ink cartridgeaccording to claim 1, wherein the surface tension is less than 40dynes/cm at 25° C.
 6. The ink cartridge according to claim 1, whereinthe surface tension is between about 36 dynes/cm to about 40 dynes/cm at25° C.
 7. The ink cartridge according to claim 1, wherein the liquid inkhas a viscosity at 25° C. greater than 2.0 cp.
 8. The ink cartridgeaccording to claim 1, wherein the liquid ink has a viscosity at 25° C.is between about 2.5 cp and 3.5 cp.
 9. An ink composition comprising: acolorant and an aqueous carrier, wherein the ink composition has adissolved gas content of less than 3 ppm as measured on the basis of theamount of dissolved oxygen gas at 20° C. at 20° C., a static surfacetension at 25° C. of greater than 34 dynes/cm, and an advancing contactangle relative to an ink receiving receiver of less than about 55° atroom temperature.
 10. The ink composition according to claim 9, whereinthe dissolved gas content is less than about 1.0 ppm as measured on thebasis of the amount of dissolved oxygen gas at 20° C.
 11. The inkcomposition according to claim 9, wherein the surface tension is betweenabout 36 dynes/cm to about 40 dynes/cm at 25° C.
 12. The ink compositionaccording to claim 9, wherein the liquid ink has a viscosity at 25° C.greater than 2.0 cp.
 13. The ink composition according to claim 9,wherein the viscosity at 25° C. is between about 2.5 cp and 3.5 cp. 14.The ink composition according to claim 9, wherein the colorant includesa dye.
 15. The ink composition according to claim 9, wherein thecolorant includes a pigment.
 16. The ink composition according to claim9, wherein the surface tension is less than 40 dynes/cm at 25° C. 17.The ink composition according to claim 9, wherein the advancing contactangle relative to an ink receiving receiver of less than 30° at roomtemperature.
 18. A method of filling an ink cartridge comprising:providing a housing having a front side wall, a back side wall oppositethe front side wall, a pair of opposed left and right side wallsseparating the front and the back side walls, and a bottom wall, thewalls defining an internal cavity within the housing; providing an inkcontainer; positioning the ink container within the internal cavity; andfilling the ink container with a liquid ink having a dissolved gascontent of less than 3 ppm as measured on the basis of the amount ofdissolved oxygen gas at 20° C., a static surface tension at 25° C. ofgreater than 34 dynes/cm, and an advancing contact angle relative to anink receiving receiver of less than about 55° at room temperature. 19.The method according to claim 18, wherein the container is a collapsiblebag.
 20. The method according to claim 18, wherein the dissolved gascontent is less than 1.0 ppm as measured on the basis of the amount ofdissolved oxygen gas at 20° C.
 21. The method according to claim 18,wherein the surface tension is between about 36 to about 40 dynes/cm.22. The method according to claim 18, wherein the liquid ink has aviscosity at 25° C. greater than 2.0 cp.
 23. The method according toclaim 18, wherein the viscosity at 25° C. is between about 2.5 and 3.5cp.
 24. An ink cartridge comprising: an ink container filled with aliquid ink, the liquid ink having a dissolved gas content of less than 3ppm as measured on the basis of the amount of dissolved oxygen gas at20° C., a static surface tension at 25° C. of greater than 34 dynes/cm,and an advancing contact angle relative to an ink receiving receiver ofless than about 55° at room temperature.
 25. The ink cartridge accordingto claim 24, wherein the ink container includes a bag.
 26. The inkcartridge according to claim 24, wherein the ink container includes arigid housing.
 27. The ink cartridge according to claim 24, wherein theadvancing contact angle relative to an ink receiving receiver is lessthan 30° at room temperature.
 28. The ink cartridge according to claim24, wherein the liquid ink includes a dye.
 29. The ink cartridgeaccording to claim 24, wherein the liquid ink includes a pigment. 30.The ink cartridge according to claim 24, wherein the surface tension isless than 40 dynes/cm at 25° C.